Extrusion device



May 7 1940- F. P. KRETcHMr-:R 2,199,825

EXTRUS ION DEVICE Filed Sept. 18, 1937 Patented May 7, 1940y IUNITEDSTATES PATENT 4ol-FlcE 6 Claims.

. ducing an integral extruded section having spaced interior aperturestherein, which device may be employed for the extrusion of plasticmaterials in general.

Another object of the present invention is to provide an extrusionnozzle capable of producing a tubular product with one or more tubularintegral portions radially spaced from the axis thereof.

It is a further object of the present invention to provide an extrusiondevice, such as the above, wherein the orifice is so designed as toproduce a product wherein the spaced tubular portions may be relativelyrotated during extrusion so that the resulting product comprisesspirally arranged portions and wherein means is provided, in combinationwith the extrusion oriflce, to support all of the tubular portions ofthe extruded product during and after extrusion from the interiorthereof so as to maintain their symmetry and tubular form free fromdistortion or interior adhesion While being twisted and/or conveyed lrom the device.

Numerous other objects and advantages will more fully appear during thecourse and progress of the following specification.

Referring to the drawing:

Fig. l is an elevational View of an extrusion machine constructed inaccordance with the present invention.

Fig. 2 is al sectional elevation taken on the line 2-2 in Fig. l.

Fig. 3 is a sectional elevation taken on the line 3--3 in Fig. 1.

Fig. 4 is a sectional elevation taken on the line 4-4 in Fig. 3.

Fig. 5 is a vertical sectional elevation taken centrally through analternative type of extrusion device. l

Fig. 6 is a perspective view of the nozzle shown in Fig. 5.

Fig. 7 is a sectional View showing the product produced in accordancewith the above machine.

The device, shown in Figs. 1 to 4 of the drawing, comprises a structurespecifically constructed for the purpose of manufacturing twistedlicorice candy but it will be apparent that this structure is merelydescribed for, the'purpose of illustrating the present invention whichmay be equally well applied to the manufacture of any other extrusionproduct having integral, spaced, tubular (Cl. 10T-14) portions andparticularly wherein certain ofthe tubular portions are desired toreside spirally with respect to the axis thereof. The structure shown inthe figures comprises a pressure device I0. interiorly of which isprovided a body of the 5 plastic material to be extruded, in this case asuitably prepared and cooked body of licorice or other plastic candy.Pressure containers of this type are commonly known and are providedwith pistons; spiral compressors or other pressure-ap- 10 plying meansin order to force the licorice through the extrusion orifice andaccordingly these details are not shown.

An extrusion die or orice constructed in accordance with the presentinvention, shown more 16 clearly inFigs. 2 and 3, and designatedgenerally by the numeral I2, comprises a cylindrical body portion I4having a front face I6 in which is formed a central, cylindricalaperture I8 and a plurality of smaller cylindrical apertures 20 ar- 20ranged about the circumference thereof and so formed that they residetangentially of the periphery of the central aperture. More specically,the outer apertures 20 are drilled in the front face i6 so that theapertures formed thereby are 25 continuous with the central opening I8,as a result of which plastic material extruded under pressuretherethrough will provide a continuous, integral section.

According to the present invention, however, the portions extrudedthrough the various cylindrical apertures are to be tubular-in nature;that is, to comprise a central void or hollow space throughout theirlength and to this end means is provided centrally of each of theaforementioned apertures for maintaining this tubular coniiguration.

Thus, as shown clearly in Figs. l, 3 and 4, the cylindrical pipe orconduit 22 is arranged coaxially with the central aperture I8 and isrigidly 4o secured to the cylindrical body I4 of the ex trusion'die bymeans of the plurality of radially extending struts 24 which areannularly spaced so that they will not interfere with the free iiow ofthe plastic material from the interior of the i plastic container -tothe extrusion apertures. Each of the struts 24 is provided with acentral bore communicating with the interior of the conduit 22 forsupplying air under pressure from a source which will be hereinafterdescribed more. in'detail.

' The conduit 22, as viewed in Fig. 3, is sealed y at its lefthand endso that the air draft will be directed interiorly of the plastic tubularmemy of the through the aperture I8. In other words, the annularvtubular section thus produced by extrusion will be maintained inextended position by the fluid pressure introduced centrally thereof.

Substantially the same eiect is produced with regard to the radiallyoffset apertures 20 through the agency of the jets 28 which are providedwith a central bore 38 extending almost to their inner end. Each of thejets has a reduced diameter adjacent the vicinity of the apertures 20equal to the interior diameter of the respective tubular portion inthevflnal extruded article. These jets are supported in a radiallyinwardly extending. annular flange 32 of the tubular member I4 and aresecured rigidly in suitably spaced apertures co'-'axia1 with theapertures 20.

According to one'method of manufacturing the present device, a pluralityof the aforesaid apertures 33 may be bored in the flange 32 (in thepresent embodiment, six in number) and the jets 28 forced therein underpressure. Radial bores extend inwardly from the periphery of thecylindrical member'l4 and interconnect With the central bore. 30 of thejets for supplying compressed air thereto in the manner aforementioned.As shown more clearly in Fig. 4, the inwardly extending annular fiange32 is relieved intermediate of the jet supporting portions, as indicatedby the numeral 36, so that the plastic material to be extruded will findready access to the annular space 38 and thus provide an adequate supplyof material for feeding the apertures 20.

The present extrusion die is rotatably positioned in a suitablecylindrical aperture in the wall I0 of the pressure container and isprovided with an integral spur gear 40 so that it may be continuallyrotated, the parts being maintained in the position shown' during saidrotation by means of the face plate 42' rigidly secured in spacedrelationship with respect to the front wall I6 by means of the studbolts 44. As clearly shown in Fig. 3, the face plate 42 removablyretains the entire extrusion die rotatably within the bearing aperturein the member I0. For rotating the assembly, the gear 40 meshes with thegear 46 whichin turn is rotated by the gear 48 from any suitable source(not shown).

It will be noted that the structure shown in Fig. 1 comprises a seriesof four extrusion units mounted on the same pressure device I0 andoperable from the same gear 48. The compressed air jets are suppliedthrough the agency of the ducts 50 and 52, which are formed in the wallof the device and extend to any suitable fitting for connection to acompressed air machine. Each of the ducts 50 terminates in an annulargroove 54 formed completely about the interior surface aforementionedcircular aperture in which the cylindrical portion I4 of the die isrotatably supported. Since the annular groove 54 is so arrangedas tocoincide with the bore 26, air is continually supplied theretoregardless of the rotational position of the die. The ducts 52 similarlyterminate in annular grooves 56 which register at all times with thebore 34, thus supplying the jets 28 with a continual blast of air duringrotation of the device.

In operation, the rotatable extrusion dies are all set into continuousrotation through the agency of the gears 48, 46 and 40, at which timethe plastic mass interiorlyof the container I0 passes through theannular space between the tube 22 and the inner wall of the cylindricalbody I4 and past the supporting struts A24. Upon reaching the inwardlyextending ange member 32, the mass continues 'to ow vthrough therelieved or cut-away portions 86 and through the space adjacent theouter wall of the tube 22 and into the annular space 38 ln which aresituated the jets 28.

The material, as itsubsequently issues through the apertures I8 and 20,will obviously possess the sectional configuration shown in Fig. 7,namely, comprising a central, cylindrical, tubular portion 58, about theperiphery of which are spirally arranged six smaller tubular portions60. As this section issues from the nozzle, the air under compression isforced continually from the bore 30 of the jets 28 and the pipe 26, as aresult of which the product is maintained in the form shown in spite ofthe deforming and twisting stresses applied, as mentioned above. Theproduct, as formed, may be continually conveyed or removed in anyconventional manner.

According to the alternative preferred embodiment shown in Figs. 5 and6, the die portion 62 is readily separable from the remainder of thedevice for cleaning and adjustment and comprises a cylindrical portionhaving apertures I8 and 20, as defined heretofore in detail. Jets 28,arranged in substantially the same manner as aforementioned, communicatewith ducts 64 which open rearwardly of the unit, as shown in Fig. 5. Thedie is in turn supported in a sleeve member 56 in the wall I0 whichisprovided with a plurality of ducts 68 normally registering with theducts 64 and driving a supply of air under pressure through the agencyof the annular xedly positionedjbeing mounted upon the conf duit 'I2mounted interiorly of the pressure chamber of the device by means of.brackets (not shown) and extending through the walls thereof to thesource of compressed air; It will be apparent that, in operation, theplastic mass will be forced through the annular space I4 and outwardlyof the extrusion orifices in the manner aforementioned.

The present invention providesa device which is simple in structure, yetcapable of producing a novel form of extruded product free fromimperfections. 'I'he present device lwill obviously find many uses inthe formation of extruded products having integral, yet spaced, tubularportions and the present invention comprehends the application thereofto any such uses.

The instant device is particularly applicable i to the manufacture ofcandies and especially plastic licorice products of the class sometimesreferred to as twists. Articles of this class find increasing popularitywhen they are formed with thin wall sections which seem to render themof increased palataloility.` Such a confection produced in the instantdevice, while possessing relatively thin walls throughout, has aconsiderable interior and exterior surface area and is surprisinglylarge in'appearance with respect to the actual amount of materialemployed per unit section. y f

Moreover, it has been found that the provision of the multiplicity ofjets enables the formation of a product with tubularr portions havingunusually thin walls which are retained in the normal tubularconfiguration shown, by the applied draft of compressed fluid eventhough subjected to considerable strain by the twisting action of theextrusion device or by the conveyors.

While compressed air has been mentioned above, it will be obvious thatany equivalent uid could be employed for distending the extrudedproduct. Futhermore, the shape and configuration of the extrusionapertures may be varied within wide limits. It is preferable, though not essential, to extend the tube 22 slightly outwardly from the face ofthe die I6, as shown in Fig. 3.

It is thought that the invention and numerous of its attendantadvantages will be understood from the foregoing description and it isobvious that numerous changes may be made in the form, construction andarrangement oi the several parts without departing from the spirit orscope of the invention, or sacricing any of its attendant advantages,the form herein described being a preferred embodiment for the purposeof illustrating the invention.A

The inventionfis hereby claimed as follows:

l. An extrusion device comprising an extrusion die having an annularextrusion aperture therein, a second annular aperture oilset from saidfirst mentioned aperture but continuous therewith, means for rotatingsaid die as a unit to produce a twist, means for supplying a plastic tosaid apertures, and conduit means centrally of each of said aperturesfor Isupplying centrally of the extruded plastic a filling material.

2. An extrusion die having an extrusion orice therein, a furtherextrusion orifice intersecting the periphery o1' said ilrst namedorifice and continuous therewith, means for rotating said die as a unitto produce a twist, means for supplying a plastic to said extrudedportions, and conduit means centrally of each of said extruded -portionsfor supplying a iluid under pressure centrally of the extruded portions.

3. An extrusion die having an annular extrusion orince therein, said diehaving a further plurality of annular extrusion oriilces arrangedoutwardly of said ilrst named orifice and interv 3 seating the peripherythereof, said plurality of orices being arranged tangentially withrespect to said ilrst named orifice and being continuous therewith,means for rotating said die as a unit to produce a twist, means forsupplying a plastic to said extruded portions, and conduit meanscentrally of each of said extruded portions for supplying a iiuid underpressure centrally of the extruded portions.

4. An extrusion device comprising an extrusion die having an annularextrusion aperture CFI therein, a second annular aperture offset from ysaid iirst mentioned aperture but continuous therewith, said die beingrotatable about the axis of said aperture to produce a spiral product,means to rotate said die during extrusion, and means for continuouslysupplying fluid under pressure centrally of each of said annularapertures while thedie is rotated.

5. An extrusion die having an annular extrusion orice therein, said diehaving a plurality of annular extrusion oriiices arranged outwardly ofsaid rst named orice and intersecting the periphery thereof, saidplurality of orifices being arranged tangentially with respect to saidrst named orifice and being continuous therewith, means to i'eed plasticmaterial to said die for extrusion, means to continually rotate said dieabout its axis, and means for continuously supplying uid under pressurecentrally of each of said annular apertures while the die is rotated.

6. A rotatably mounted extrusion die having an outer face, an apertureof circular section centrally and axially arranged upon said face, aplurality of additional circular apertures arranged about the peripheryof said first named aperture and extending outwardly therefrom butcontinuous therewith, uid supply conduits arranged centrally of said'second named apertures and being of lesser extent than said apertures toprovide an annular extrusion space thereabout, means to rotate said dieduring extrusion, and means to supply said conduits with uid underpressure to maintain a. tubular section in the material extrudedtherefrom.

FRANK P. KRETCHMER.

